Method for using a conductive tungsten nitride etch stop layer to form conductive interconnects and tungsten nitride contact structure
US6001726A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1997 |
| Grant date | Dec 14, 1999 |
| Priority date | — |
| Expiry date | Mar 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76885
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming a contact structure (10) which enables the use of ultra-shallow source/drain junctions begins by forming source and drain regions (14) and gate electrode (16). The source and drain regions (14) and the gate electrode (16) are silicided to form silicide regions (20). A conductive tungsten nitride etch stop layer (22) is formed overlying the silicide regions (20). Contact plug regions (28) are then formed to contact to the etch stop layer (22) and silicided regions (20). At this point, all of the silicide regions (20) are electrically short circuited. To remove this electric short circuit, an isotropic etch process comprising hydrogen peroxide, ammonium hydroxide, and water is used to remove portions of the tungsten nitride regions which are between the individual contact portions (28) in a self-aligned manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.